A name for calling someone (usually a female) for being a total bitch and is always crabby. such as a girl on her period. originated from an episode of RvB when talking about a really bitchy girl named Tex on the Blue team.

Well Bitchpants McCrabby was as bitchy as always.
Your not Helping, Bitchpants McCrabby.

Tucker:{trying to communicate with the alien}" I am Tucker. This is Church. That's Bitchpants McCrabby." {points over to Tex}